This project is designed to research and develop means for the early detection of impending roof falls in underground mines and means for alerting maintenance crews to take proactive action to prevent disaster, thereby saving lives and preventing injuries to miners. This will be achieved by attaching sensors to roof bolt mounting plates. The sensors will detect structural changes in the roof infrastructure and will provide an alarm signal when a critical level of damage, that requires maintenance attention, has occurred. For the long-range program, the objective is to provide an audible alarm in the maintenance office as soon as the damage to the structure occurred, and display on a video screen the location where the problem exists in a pattern that specifies the degree of infrastructure weakening that took place. The immediate purpose of phase 1 of this proposal is to study the feasibility of this approach inside an active mine, to see if results that were obtained in the laboratory can be translated to real-life situations. To study the feasibility, the sensor response to an induced roof fall near a long wall in an underground mine will be evaluated using specially designed, built, and MSHA approved instrumentation. MSHA-approved sensors will be mounted on roof bolt mounting plates near the longwall together with MSHA-approved preamplifiers. The amplifier output voltages will be carried through MSHA-approved wires from the hazardous area to a safe area where the signals will pass through MSHA-approved barriers to amplifiers that will feed the signals to recording equipment. The signals will then be analyzed for association with damage. PUBLIC HEALTH RELEVANCE: The most prevalent cause of fatalities in underground mines is roof fall. Roof falls also cause thousands of injuries every year. There are about 2000 roof falls annually 1 in the U.S. This project is designed to devise means for the early detection of impending roof falls and provide alarms to alert maintenance crews to take proactive action to prevent disasters.